Note On, Note Off, Velocity

The three messages you use most:

• Note On: 'start a note now' with a specified pitch and velocity.
• Note Off: 'stop that note'.
• Velocity: how hard the key was pressed (0-127). Most instruments map velocity to loudness or brightness.

Note On  | Channel 1 | Note 60 (Middle C) | Velocity 96
Note Off | Channel 1 | Note 60            | Velocity 0